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Caca

Non-Circulating Hydroponic Method

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Hi

 

 

Anybody else tried this? I have boxes built but not lined with plastic yet. I will post more when i have them up and going.



Jens

keep posting

 

I'm gonna try this week, but......

Everything here is against good results.

1) Cold months are here,days are shorter.

2) I cant find recommended NPK ratio here

Plan is to set boxes with different NPK ( what is available here). One box will be NPK 16-11-24, second 14-11-25 and maybe one with organic fert.

ALL with aeration.

 

 

Cheers

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Hi,

 

If I understand it correctly, the Kratky method is intended for hydroponics exclusively.......using clean water and packaged nutrients.

 

I suggest that, if you used fish tank water.....and it was static......and without aeration, you'd quickly get dramas because of the organics in the fish water.

 

Having said that, I'd like to try the method.  On those occasions where I've used hydroponics (in several of its various configurations), I've been able to grow a lot of food quite cost-effectively. 

 

Gary

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Hi Gary

 

 

I suggest that, if you used fish tank water.....and it was static......and without aeration, you'd quickly get dramas because of the organics in the fish water.
 

agree 100%,

but...............maybe there is a way.

If you do sterilization with hydrogen peroxide or chlorine (or even boil the water). Then use protein skimmer.

Also before all that, adding worm or compost tea in fish water to boost nutrients.

 

cheers

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Hi Caca,

 

There is already a "Kratky"-style approach to aquaponics.

 

It's like a raft system except that, rather than floating on the water, the raft rests on the sides of the raft tank.  The water flows through the tank (just like any other raft tank) but the level is reduced as the plants (and their roots) grow.  This creates an "air gap" similar to the Kratky method.....and appears to offer similar benefits.   The grow tanks are aerated.

 

I think the "air gap" idea had its origins in hydroponics systems in Israel.......many years ago.  This idea was pioneered in aquaponics by Martin O'Dee (arising out of discussion of the method between he and I)......and is a feature of his commercial system design.  You can see photos of the grow tank....here.

 

Martin, who spends much of his time pursuing other business interests in Asia, is relatively little known in the aquaponics world......largely because he's smart enough to avoid forums. :wink:   At last count, he had established three commercial systems in Australia.  

 

In 2009, Martin brought Dr James Rakocy to Australia for a Commercial Aquaponics course that also featured Dr Brett Roe, Dr David Moriarty (a probiotics expert), Martin and myself. 

 

 

Gary

Edited by GaryD (see edit history)

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Hi,

 

If I understand it correctly, the Kratky method is intended for hydroponics exclusively.......using clean water and packaged nutrients.

 

I suggest that, if you used fish tank water.....and it was static......and without aeration, you'd quickly get dramas because of the organics in the fish water.

 

Gary,

 

From what I have read the Kratky is only for use with inorganic salts as nutrients. I totally agree that not having aeration with organics in the water would get stinky quite quickly. Is there a benefit of having the "air gap" in conventional aquaponics with aeration and water flow? Or, would floating rafts work just as well because the water is oxygenated by mechanical aeration? Is the center ridge in the grow tanks you linked to, made to support the raft and allow for that "air gap"

 

I am really interested in the Kratky method because of its simplicity. Mix nutrients in tank, set seedlings in tank, in 6-8 weeks harvest. No water or air pumps, no clogged water lines, just "set it and forget it," if i may borrow from a Ronco infomercial.

 

Jens

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Hi

 

 

I am really interested in the Kratky method because of its simplicity. Mix nutrients in tank, set seedlings in tank, in 6-8 weeks harvest. No water or air pumps, no clogged water lines, just "set it and forget it," if i may borrow from a Ronco infomercial.



Jens

Exactly 

No power,works indoor & outdoor, no labor, you can grow lettuce,tomato,cucumber......and lettuce can grow in 5 liter bottle because need 4 liter for their lifespan, so you can do the math how many liters you need for box. ;) .....and you are welcome. :D

Regarding inorganic fertilizers, I'm not happy to use them as main nutrients or supplement, but I will use them until I figure it out ( or somebody else ) how to use organic fertilizers.

 

I start this tread for reasons mentioned above

and hope that in future some of us try it and exchange experience. So keep posting.

 

good luck &have fun

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Hi,

 

Is Martin O'Dee and Israelis do non-circulating method ?

 

Martin doesn't......his systems function like conventional raft systems.  As for the Israelis, they are among the most proficient hydroponicists on the planet....borne of the harsh environment in which they grow.  They use many methods but I can't be sure that the Kratky approach is one of them.

 

Is the center ridge in the grow tanks you linked to, made to support the raft and allow for that "air gap"

 

It's intended to support the "raft" along its centre line.  The raft rests on the top of the grow tank and the depth of the water is controlled through the use of weirs (PVC pipe of various lengths).   As the plants (and their roots) grow, the water level is manually lowered to create the air gap.

 

Plants absorb more oxygen directly from the air than from the oxygen in water.  The air gap method allows plant roots (aerial roots) to absorb large quantities of oxygen while also allowing the uptake of nutrients (through the water roots).  The main benefit of the air gap method is (allegedly) very rapid growth.  I haven't done a comparison between the air gap method and a conventional DWC raft system so I can't speak to the claims about growth......but it makes sense.

 

If you don't have sufficient dissolved oxygen in a raft tank, the plants will be stunted.  In 2009, I visited a commercial system (in the company of several people (including Dr James Rakocy) where you could look along the length of the grow tanks at the fluctuating height of the basil plants that were growing in the tank.  The operator asked JR why this pattern of growth occurred and his response was that, if the operator put air stones at the low point in the fluctuation, then the plants would all grow to the same height.

 

Taking this one step forward, if you have an air gap between the raft and the water level, then you are assured of plenty of readily available oxygen for the plant.

 

Gary

 

 

Edited by GaryD (see edit history)

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Hello all,

 

This air gap business is something that makes perfect sense to me. I have recently learned the hard way that many vegetable plants do not like having their roots entirely submerged.  It appears to me, no matter what growing system, that one thing is constant:  The top part of the root ball, and maybe even a larger portion of the root, must not be waterlogged.  For gravel grow beds, I experienced what happens when the water level is too high.  I've had personal experience with a flood and drain cycle being too fast and essentially keeping everything wet, to constant flow with the water level too high.  In both of these scenarios, drying the top of the roots made a huge difference.

 

The one I am not sure about is DWC.  I think many people use air stones in the water to achieve a high dissolved oxygen level perhaps?  It could be that the root top is still in the container and not fully submerged?

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Caca, i have been thinking about how one could use organic nutrients in the non-circulating hydro and it seems that as long as you did keep it aerated that would keep the solution from going anaerobic and stinky. Similar to the way you keep compost tea going.

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Thank you  Jcnielsen4

Yes, aerated water will prevent anaerobic process. That is not the only problem with organic ( natural ) fertilizers. When you put  org fert in water you also put zillion things that you don't want in water ( plants). Some of then can do more harm to your health then inorganic fert. Sterilization is a must.

Second, ogr fert are low in NPK ( usually 5-5-5 ) and micro nutrients.

 

Good luck & have fun

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Heh, I guess I kind of did this last winter. I had cut holes in a rubbermaid tote lid last year and was seeing how solids emptied into a tank with an air stone would work at growing.  I put bibb lettuce seedling in and had the intention of  manually transferring water between the fish tank if the nitrate levels dropped.

 

Well, as I often do, I got off to tilting at a different windmill and forgot about it for a few weeks and my plants had bolted. I collected lots of seeds and noticed that  they started dying  on me. I had not forseen the need to leave one hole open to check the water level and the level had dropped to the point the roots no longer kept up with around 9-10 inches, didn't measure so this is a best guess.

 

  I called myself a bunch of stupid names and went about to focusing on the out door system. Anyhow, thought you should know, it has worked once with aquaponic water and an airstone. I may have to look at it again now after finally reading this thread..

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I saw some youtube clips from a guy who is experimenting Kratky method with aquarium water.  He's only growing 1 pepper plant and changes the water once a week.  He's very happy with the results.  I will look for the videos and post them.  I'm going to try Kratky this coming spring as I am trying to do as much off grid as possible.  Also plan to try a solar power DWC hydroponic system.  That way no fish are at risk if I screw it up.  :-)

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Hi Sam

I'm so sorry but I didn't take picture, I was preoccupied with installing heating system in my house, so in one word this method is fantastic.

I was a little skeptic at first because my setup is created in a hurry (bim,bam,bom....done in 15  min) but lettuce is fantastic, celery and chard also.

So greens can be grown 100% successfully, and in spring still need to try tomato ,cucumber,etc.

As I wrote earlier I don't have the same fertilizes as Kratky use, but it seems that this method is flexible in more that one ways.

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post-1719-0-89871100-1389652504_thumb.jpI have finally finished my first growing box. It is 4ft by 4 ft by 6in deep. I lined it with weed cloth and then two layers of 6 mil plastic. Cut holes in the styrofoam on 4 in centers, shifted 2 in one way on alternating rows. I put two week old seedlings in the water Jan. 7th, 2014. I can't wait to see how they do.

 

Jcnielsen4

 

 

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